1. Field of the Invention
The present invention relates to surgical stapling and cutting instruments adapted for use in the diagnosis and therapy of pathologies treated by stapled resection. More particularly, the invention relates to a guided knife for use in a surgical stapling and cutting instrument.
2. Description of the Prior Art
Surgical stapling and cutting instruments are commonly utilized in the diagnosis and treatment of pathologies treated by stapled resection. Surgical stapling and cutting instruments provide a mechanism to extend the transluminal exploitation of mechanical suturing devices introduced via the anal canal, mouth, stomach and service accesses. Although surgical stapling and cutting instruments are most commonly utilized with rectal pathologies, surgical stapling and cutting instruments may be used in a variety of environments.
Over time, surgical stapling and cutting instruments, in particular, curved surgical stapling and cutting instruments, have been developed. These instruments generally include a support frame, an anvil attached to the support frame and a cartridge housing carrying a plurality of staples. The instruments also include a driver within the cartridge housing which pushes all of the staples out simultaneously into the anvil to form the staples into a generally B-shape, suturing tissue together. In addition, these instruments include approximation mechanisms for moving the cartridge housing from a spaced position from the anvil to accept tissue therebetween to a closed position where the tissue is clamped between the anvil and the cartridge housing. Finally, the instruments include a firing mechanism for moving the driver forward to form the staples against the anvil.
Current surgical stapling and cutting devices have a centrally located knife with at least one staple row on each side of the knife. It is desirable to obtain a complete cut with no or minimal tagging (thin strands of tissue joining the two sides of the cut) when the instrument is actuated. The knife of the surgical stapling and cutting instrument is advanced in conjunction with the staples of the instrument as it is fired. The knife penetrates a plastic cutting washer during the final stroke. This penetration cuts any tissue between the knife and the washer.
However, this happens only if the knife is aligned with the washer. As such, a system for aligning the washer with the knife is needed. Such a device would ensure quality cuts and minimize tagging by keeping the tissue within the arc of the knife and between the washer and the knife. The present invention provides such a guided knife structure.